ah, so that's why you have the import by dates... I was unable to import my whole classroom because it has more than 150 assignments. That topic feature was perfect since I'm elementary and I could import each topic and have a grade. I'm going to rethink next year's build on classroom so I can get around this.

I think I figured it out. It has something to do with the length of the classroom name. For example, my classrooms with longer names wouldn't work. When I shortened the name, it did. it didn't like: BW B9 - Main Class/Reading, but liked BW B9 Reading.

Out of my 5 classrooms with the same students (I have them separated by subject because of the 150 assignment limitation), 3 of them worked, but 2 of them consistently comes up with the null error when I try to import students.

I'm getting that same error from one of my classrooms: Something went wrong: Cannot call method "getRange" of null. One worked, but that one won't. Trying the others now. Same students in both.